This invention relates to a trailer coupling that receives a drawbar having an annular eye and has a locking mechanism that prevents accidental displacement of the drawbar from the coupling.
Trailer couplings that receive a drawbar having an annular eye on an upwardly-projecting pintle or a hook utilize two types of latches to prevent the drawbar from becoming accidentally dislodged from the pintle. In one type of coupling the latch rotates about an axis that is horizontally displaced from the pintle, thereby allowing the latch to be rotated upwardly and permit the drawbar to be inserted below it. On the other type of coupling the latch rotates about an axis which is vertically displaced from the pintle, thereby allowing the latch to be rotated forwardly to completely uncover the pintle. The advantage of this latter type of coupling is that the latch can be opened merely by pushing the drawbar rearwardly against the face of the latch. The disadvantage of the latter type of hitch is that it is difficult to make it as strong as the former type. Examples of couplings where the latch is lifted are Blacklaw, U.S. Pat. No. 4,721,324, Weiss, U.S. Pat. No. 2,842,380, Weiss, U.S. Pat. No. 2,766,995, and FIGS. 1 and 2 of Weiss, U.S. Pat. No. 2,491,143. An example of a coupling where the latch is rotated forwardly is FIG. 4 of Weiss '143.
All of the prior art drawbar-receiving couplings have a locking mechanism that prevents accidental opening of the latch. However, these locking mechanisms are either complex, which makes them expensive, or difficult to operate, which makes them commercially undesirable, or both.
The subject invention overcomes the foregoing shortcomings of the prior art couplings by providing a body that can be attached to a towing vehicle and has an outwardly and upwardly-projecting pintle that is configured to receive the eye of the drawbar. A latch that is rotatably mounted in the body is normally oriented in a latched position where it engages the extremity of the pintle to prevent removal or installation of the drawbar. The latch is rotatable forwardly toward the body to displace it from the pintle to allow removal or installation of the drawbar.
A pawl that is rotatably mounted on the body forwardly of the latch is normally oriented in a locked position where it engages the latch and prevents rotation of the latch from its latched position. When the drawbar is to be inserted onto or removed from the pintle, the latch can be rotated by first rotating the pawl to where it does not engage the latch. In a preferred embodiment of the invention, the latch includes a forwardly-projecting tang that is engaged by the pawl. In addition, the pawl has a rearwardly-extending lip that fits under the tang when the pawl is released after the latch is rotated to its unlatched position, thereby holding the latch open. Rotation of the pawl to its unlocked position again, releases the latch and allows it to rotate back to its latched position.
In operation, a drawbar can be connected to the coupling merely by rotating the pawl to its unlocked position, placing the drawbar against the face of the latch, and urging it forwardly to where it can be placed over the pintle. When the drawbar drops over the pintle the latch returns to its normally latched position where it prevents the drawbar from being removed from the pintle. The pawl is then released to prevent rotation of the latch from its latched position. When the drawbar is to be removed from the coupling the pawl is rotated to its unlocked position, the latch is rotated to its unlatched position and the drawbar is lifted off of the pintle.
Accordingly, it is a principal object of the present invention to provide a trailer coupling that accepts a drawbar having an annular eye and has a locking mechanism that is deactivated by rotating a single pawl.
It is a further object of the subject invention to provide such a trailer coupling in which the locking mechanism can be deactivated with one hand.
It is a still further object of the subject invention to provide such a trailer coupling that is inexpensive to construct and simple to operate.
The foregoing and other objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.